The present invention relates to an electric device for eliminating the jerking of vehicles, particularly automotive vehicles with internal combustion engines and with a control member which influences the intake thereof, and particularly controls the idling intake.
In some automotive vehicles having an internal combustion engine, jerking, the cause of which has not been fully clarified, occurs when traveling at constant low speed in first or second gear. This jerking is not identical with the so-called bonanza effect in which the jerking is increased upon the inciting oscillation by the driver through improper actuation of the gas pedal. In contradistinction hereto, the rhythmic surges in torque which are to be eliminated in accordance with the invention are not caused by feedback via the position of the gas pedal but by unclarified interrelationships of intake, gasoline mixing or proportioning, ignition timing and possibly other factors. A typical jerk speed of rotation for a given six-cylinder engine is 1200 rpm.
In order to eliminate the jerking it has been contemplated to make use of a known control device for the idle speed of rotation by which the idle intake is varied in opposite phase to the deviation from the desired idle speed of rotation. Such known idle intake controls are provided in order to establish the lowest possible speed of rotation with favorable consumption and emission values and to maintain said speed constant, as closely as possible around the desired idle speed of rotation, regardless of the load resulting from additional units operated by the engine as well as regardless of other variables. For this purpose, in detail, a throttle element for instance a piston, is placed in a bypass to the intake passage of the engine, the piston being displaced by a servomotor which is fed from a differential amplifier. One input of the differential amplifier is acted on by an electric variable which corresponds to the desired idle speed of rotation while a second input of the differential amplifier is connected to a speed-of-rotation transmitter. Corresponding to the difference between the actual speed of rotation and the desired idle speed of rotation, the differential amplifier produces an electric output signal which actuates the servomotor in such a manner that the deviation in the speed of rotation is reduced.
Such conventional idle intake controls have proven insufficient for eliminating the above-described jerking. They cannot balance out, in opposite phase, the rhythmic fluctuations in the speed of rotation, in particular because of the dead time of an internal combustion engine. This is also true for unsatisfactory running attempts which have been carried out with an ignition timing point shifting which operates practically without delay and without dead time. The electric control devices for maintaining the speed of the vehicle constant, which are also known from the prior art, are even less suitable for eliminating the jerking than the idle-speed intake controllers, particularly for the reason that relatively small changes in adjustment variables can cause relatively large changes in the torque of the internal combustion engine.
The object of the present invention is, therefore, to develop an electric device of the type indicated in the introductory paragraph in such a manner that by means thereof the jerking can be eliminated or avoided as far as possible, without disturbing side effects.